Description

United States Patent Millard F. Smith Westport, Connecticut (P.O. Box 295, Saugatuck. Conn. 06882) June 24, 1968 Nov. 10, 1970 [72] inventor 2| 1 Appi. No. [22] Filed [45 Patented [54] OIL COLLECTION BOOM Primary Examiner-Reuben Friedman Assistant Examiner-C. M. Ditlow Attorney-Robert H. Ware ABSTRACT: An oil-absorbing boom for the purpose of collecting and removing from water thin films of oil comprising an elongated flat tubular sleeve of polymer netting enclosing within itself a plurality of flat elongated slabs or bats of picker-lap" fibrous polymer material such as blown polypropylene film arrayed end to end within the tubular sleeve and sufficiently spaced apart to permit accordion folding of the sleeve at fold lines between adjacent bats, with a tension-bearing rope or cable being positioned within the tubular sleeve alongside the successive plurality of absorbent bats to reinforce the structure for carrying its own weight or impact loads placing it in tension between its ends.

Patented N'o'i). 10, 1970 Sheet v INVENTOR.

#4120117 57m /2 BY HTTOHNFYS.

' skimming-type. oil' film recovery devic'esfhas a g on. cotmc rros aoom ascxoaous'oor rnsmvsunon The problemofjspilled oil in seaports where oil is transferred daily from tankers to shore installations or other water borne petroleum transport vessels has becomefincreasingly serious in recent years. Pollution of harb or w'a'ters has become the subject of new laws andi increasingly firm administrative action in many localities. Oil spill booms such. aszthose shown in Millard SmithUS. Pat. No. 3,I46,-598 generally serve well to contai an inadvertently. spilledfrom ruptured hose or a leaking fittingduring. the normal t ansfer of petroleum to and from waterborne transport vessels. Occasional leakage passed by conventional oiI spiII booms which may be caused by a local water-disturbance such as a vessels wake, some, times permits the cad apeoflsmalhquantitiesof'oil from a spill which. is otherwise successfully contained. Thisescapin'g-oil spreads ontthe surfaceof'the water'in anextremely thinfilm,v

I makingit very, difficult to remove. The resulting deposit of oil along. shores, beaches and waterside installations creates an important sourceof liability for the operatorsof oilrefineries, tankers. and oil transfer; installations, and the needffor gone longrunr filled,

I QBJECTSIOFTHE' INVENTION Accordingly aiprincipalobjectof the invention is to provide an oil recoveryiboom capable? being conveniently v deployed downstream inthepathiOf current-carriedfoil film slicks to absorb these;slicks; Nfurther. objectlofl theinvention'is to provide-systems and apparatus cooperating with such oil absorbing boorns for the r emoval oflthe boomcarryinggbsorbed oil from the surface of the water, andfor'separat'ingthe absorbed oil from the absorbingwhich maythenbeprepared for reuse, to beredeployed as required.

0ther and .more specific objectswill be apparent from the features, elements, combinations and operating procedures the drawings.

. disclosed in ithefollowing; detailed deseription-andlshown in 0101 La high molecular'weight polymer formed into fine randomly oriented fibers in a but of fiber material referred to as picker-lap", incorporating fibers having a 2.5 denier, 2 inches long in average length. Similar Avisun polypropylene polymers passed through blown film apparatus at extrusion temperatures in the range between 425 and 450F. produce blown film which may be formed into thesam'e type of extremeiylightwei ght compressible fluffy fibrous bats. Since the specific gravity of polypropylene is about 0.90, these bats of material are bouyant and well adapted to serve as floating oil collection structures. v I p In the boomsof the present invention, such as the boom 10 illustrated in the FIGS, a greatly elongated tubular net sleeve Ifl encloses a-series of wide, flat, thin, elongated bats 12 of this expanded polymer material'just' described,-as shown in FIGS. 3,4 and 5. The tubular net sleeve 11 is preferably formed of sii'nil'ar' lightweight'polyr'ner fibers which may be heat sealed in net configuration or' which maybe woven or knotted like a fishermans net in the form and spacing desired. The bats I2 are spaced apart longitudinally within the tubular sleeve 11 by a distance offrorntwoto three times their thickness to permit accordion folding in the manner of the accordion folded oil spilljboom shown in my U. S. Pat. No. 3,146,598. In the fabricationprocess illustrated in FIG. 4, a roll 13 of the netting materialll is un'rolled'to draw a length of this material over a work stationwhere a bat I2 is laidlengthwise along one-half of the net 11 drawnfrom the roll ISLAlong the inner edge of the bat I2"; a'tensioncable preferably formed of stainless steel wire rope 14unreeledfrom a storage reel' l6 is alsolaid longitudinally downthe central portion of the net 11 beside the bats 12. The free h'alfof the net 11 is then folded across the upper surface of the bat 12 at fold point shown in FIG; 4, en-

closingthe'cable 14 andoverla'pping 'to bring the opposite 1 edges of the net l 1 into juxtaposed relation. Net 11 thus forms a tubular sleeve'enclosing'the bat 12, with a heat sealed or stitched edge'seam" joining these two'juxtaposed net edges along the boomedge I7 shownin FIGS. 4 and'S, on the oppositej edge of theelongated bat 12 from the edge beside whichcablev 14 is laid. If desired a'comparable seam may be stitchedor heatsealed between cable 14 and'bat 12 to form a small cable hem or pocket positioning the cable along the v aligned edges of all of the bats 12*along the entire length of the boom 10.

The longitudinalspacing of the bats 12 within the tubular sleeve 11 is maintained by the formation of transverse seams between the bats 12. As shown in FIG. 4, these seams are preferably formed atthe time the boom is fabricated. As the net 11 passing the'fold point I 1&1 is formed into a sleeve by'the sewn or heat sealed seam 17 along thefull length of the bat 12, a pair oftransverse-seams are preferably formed. The first is a rearend 'seam l 8"extendingtransversely across the tubular' sleeve l l at a point directly behind the bat l2, bringing its upper andlower surface'sinto juxtapositionland stitching or heat-sealing them togetherto flatten the sleeve. At a point ing the preferredlsteps in the fabrication of an oil collection boom'of.thepresentinventiontand FIG. 5 is a'greatly enlargedcross-sectional elevation view of an oil collection fabricated'jby 'theprocess illustrated schematically in-FIG; 4-511 i compaass' alifiao a coe EcTioNsoos is The booms of therpresent; inventiomtake'advantage of the substantial interstitialvolume incorporated'in' light weight bats of polymer fibers or blown polymer'film' ofsuch materials as polypropylene which present enormous fiber surface area on which-oil filr'n deposits. itselfwhenjapassing current of water. on which such a bat floats carries afilrnofoil into contact with the bat. When this occurs,'.m'ost or all oftheoil film is collected upon the -fibrous surfaces inside the bat zand verylittleoil proceeds downstream beyond thestructurei The oil collection. booms of-thewpresent invention incorporate a'plurality ofelongated, flatprectangular bats of'such material, which rnayibe forexample Avisun polypropylene slightly spacedlengthwisealongithe flattened'tubular sleeve toward the next-"bat I2, afron'ten'dseam I9 likewise extends transversely'acrossthe flattened sleeve to form the'forward .edge of a pocket enclosing the next bat 12, as shown'in FIG. 4.

The seams l8ian'd l9'are spaced apart longitudinally by a distance sufficient to permit the boom to be accordion folded ina'stacksuch asstack 28 shown in FIG. 2 for storage and shipping. The distance between seams l8 andl9 should '1 pr'eferablybe at least'equal to the thickness of bats 12 to per-' mit this accordion'folding. Cable l4 may be caught at seams l8 and '19 if desired. 7 I

Suitable end fittings such as towing loops or shackles are preferably joinedtothe'extreme ends of thecable 14 by swaged thirnble fittings; eye splices or other common wire rope'connection techniques.

As shown in FIG. 1, the completed boom 'is preferably deployedacross'themajor part if not the entire width of'a flowingbody of water at a point downstream from the transfer 'terminal at which petroleum products are loaded or unloaded from vessels where spills may occur. Thus in FIG. 1 a tanker 20 is shown in oil transfer position beside a dock 21, surrounded by an oil spill boom 22. Arrows 23 show the direction of the prevailing current passing the installation and the compressible collection boom of the present invention is shown deployed extending partway across the waterway from one shore toward the opposite shore at a point downstream from the tanker 20, positioned to receive oil carried downstream by the current 23.

As shown in FIG. 2, after an oil film has been brought into contact with the collection boom 10 by the prevailing current and after all or the major portion of the oil film carried by the current 23 has been caught and collected in the interstitial spaces between the loosely matted fibers of the bats 12 along the length of the boom 10, the boom may be withdrawn from the waterway by such means as the pinch roll oil separation apparatus illustrated schematically in FIG. 2. In this FIG. pinch rolls 24 and 26 which may be powered to draw between themselves the compressible boom 10 are shown in power driven operation and the boom 10 is moving from the water between the pinch rolls 24 and 26 which have the effect of compressing each of the bats 12 in turn as these bats are drawn between the pinch rolls. As a result a large portion of the collected oil is squeezed out of the compressible bats 12 into a sump 27 beneath the pinch rolls. The squeezed collection boom 10 issuing from the pinch rolls is preferably accordion folded in a storage stack 28 near the shore 29 where it is ready for prompt deployment in the event of another oil spill.

Cable 14 provides unusually high strength to the fibrous polymer structure formed by the tubular net sleeve 11 and the light weight compressible bats 12, serving to position the boom in the shape and configuration and in the direction desired for optimum oil-collecting performance.

While the objects of the invention are efficiently achieved by the preferred forms of the invention described in the foregoing specification, the invention also includes changes and variations falling within and between the definitions of the following claims.

lclaim:

l. A compressible oil-collection boom comprising in bination:

A. a porous elongated tubular net sleeve;

B. a plurality of thin flat elongated bats of compressible buoyant, oil sorbent material inside the length of the sleeve;